Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Dr. Dennis Brent Callender, M.D.

Obstetrics & Gynecology Physician in Sand Coulee, MT · enumerated 2006.

Data current as of Jul 13, 2026 · sourced from CMS NPPES

National Provider Identifier

1821157728

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Registry record

Entity type Individual (Type 1)

Name Dr. Dennis Brent Callender

Credential M.D.

Sex Male

Practice address 735 Spring Creek Rd, Sand Coulee, MT, 59472

Phone (406) 736-5391

Fax (406) 736-5391

Enumeration date Dec 6, 2006

Last updated in NPPES Jul 8, 2007

Taxonomy & licenses

207V00000X Obstetrics & Gynecology Physician Allopathic & Osteopathic Physicians · License 3953 (MT) Primary

MD · Doctor of Medicine: A physician who completed medical school (allopathic medicine), residency training, and state licensure. About the MD credential

What is an NPI number?

A National Provider Identifier (NPI) is a unique 10-digit number that CMS assigns to every U.S. healthcare provider and organization under HIPAA. Type 1 NPIs identify individual providers; Type 2 NPIs identify organizations. The NPI appears on insurance claims, prescriptions, and credentialing paperwork, and never changes, even if the provider moves or changes specialty.

Read the full guide → Validate an NPI →

Frequently asked questions

What specialty is Dennis Callender?

Dennis Callender is registered in NPPES with the primary taxonomy of Obstetrics & Gynecology Physician. The taxonomy code describes the provider's classification and area of specialization for claims and credentialing.

Is this the official NPI registry?

No. NPI Portal is a private site built on public CMS NPPES data. The official registry is npiregistry.cms.hhs.gov, operated by CMS.

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2007-07-08.